What if the rainstorm of the century hits Haarlem? 'Nearly 4,900 homes in vulnerable areas'

Recent data from the Klimaateffectatlas indicates that nearly 4,900 homes in Haarlem are at risk of flooding if a once-in-a-century rainstorm occurs. These calculations, performed by the consultancy Nelen & Schuurmans, suggest that such an event, characterized by 70 millimeters of rainfall in one hour, could leave water levels at least 15 centimeters high against the facades of these vulnerable properties. Specific areas such as the Leidsebuurt-west and the Nieuw-Guineabuurt show higher concentrations of susceptible buildings, particularly where infrastructure and socioeconomic factors increase the risk of damage. However, experts note that such vulnerability does not guarantee actual damage, as household preparation plays a critical role.

While extreme weather remains rare, historical data from the Verbond van Verzekeraars shows that Haarlem residents have already claimed over 10 million euros in precipitation-related damages since 2007. To mitigate risks, experts advise residents to replace non-porous tiles with greenery, install rain barrels, and take emergency precautions such as barricading doorways or blocking toilets during heavy downpours to prevent sewage backup.